Engine/Transmission (1994 - 1998) timing

[SEmerson]

I am setting the timing on a freinds truck. It has a 180 pump. from the base I get around 12 mm lift at tdc. What am I doing wrong? There is no way that it is this far advanced. It is qiete. :{

 

[moparguy]

Without knowing the answer to your question, the first thing I'd do is recheck TDC. I wouldn't use the timing pin, go with the exhaust valve method.



Good luck, RJR

 

[BPonci]

Do the drop valve method to locate tdc properly. Locate tdc and mark your crank pulley. Now you can set your dial indicater up and begin your procedure. Good luck. Let us know how it comes out for you.

 

[SEmerson]

If I zero the dial indicator on the base circle of the cam I get 12 mm lift at tdc. This is using the pin to fine tdc. Am i doing this right? I have done this before succesfully but it has been awhile. The dots do line up on the crank and cam gear. I have the front cover off now.

 

[mikel]

Is it possible that you have a dial indicator that is in inches instead of mm?

 

[SEmerson]

No it is the blue point kit snap on sells. It is labled in mm too. I also compared it to a caliper to see if I was reading it right.

 

[Bloomy]

Can somebody explain the exhaust valve method or the drop valve method?



Thanks

Thomas

 

[HBrunton]

set the valve lash tight, then give the adjuster screw about 1 to 2 more full turns. This will start to open the valve. SLOWLY roll the engine over by hand until you feel it stop. Make a mark on your balancer. Now rotate the engine opposite of the way you turned it all the way until it stops. Make another mark on your balancer. The distance that is halfway between the two marks is top dead center. This is alot closer than the pin method. Hope this helps.

 

[JGheen]

SLOWLY roll the engine over by hand until you feel it stop. Make a mark on your balancer. Now rotate the engine opposite of the way you turned it all the way until it stops. QUOTE]



Sorry, if I am not understanding, but roll the engine over until "what" stops? The rocker arm?

 

[biggy238]

What they are talking about is adjusting the exhaust valve of the #1 cylinder so that it is constantly open. When the piston tries to reach TDC it will hit the exhaust valve first. Do this turning the crank in both directions, making a mark where the turn stops both times. (you should have an indicator needle to make this mark) The distance between these two marks is exact TDC. When you are done Marking the two points you will need to readjust the exhaust valve to set the engine at TDC. This whole thing is the piston stop method of locating TDC.

 

[Bloomy]

Thanks for the info. That is how mine was done by Doug @ ADT. I just couldn't remember how it was done.



Thomas

 

[JGheen]

I think I am still or not reading your post right. But if the exhaust valve is always open by adjusting it to stay open how does the piston ever get to TDC? It would be stopped early by the exhaust valve hitting it. So then if you turned it back the other way you would be going back to BDC and the exhaust valve would close back up. I don't know, please explain better and forgive my misunderstanding.

 

[SEmerson]

I think I am still or not reading your post right. But if the exhaust valve is always open by adjusting it to stay open how does the piston ever get to TDC? It would be stopped early by the exhaust valve hitting it. So then if you turned it back the other way you would be going back to BDC and the exhaust valve would close back up. I don't know, please explain better and forgive my misunderstanding.

it stops before tdc. Then when you go the other way it again stops just before tdc. Then you mark in the middle of the 2 stop points.



Does any one have any help for my problem?

 

[Vaughn MacKenzie]

So then if you turned it back the other way you would be going back to BDC and the exhaust valve would close back up.

JGheen read back a couple posts. . . the exhaust valve is open for the whole engine rotation because it is way overtightened to force it open. Note: don't rotate engine past the point where it normally would open the valve because then you can cause valve spring bind/damage. In this case rotate engine 1 revolution then tighten the valve and do the procedure.



I never heard of this procedure before but it should work very well. BTW I have my head off right now doing the headgasket. . . do you think now would be a good time to mark TDC??



Vaughn

 

[JGheen]

it stops before tdc. Then when you go the other way it again stops just before tdc. Then you mark in the middle of the 2 stop points.



Does any one have any help for my problem?

Ok, I see now, I wasn't looking at the big picture. I can see now where TDC would be. Thanks. Sorry, I didn't understand the other explainations.



But does the exhaust valve really hit the piston if the lash is set that tight? If so, man, glad I don't ever set it tighter than . 020".



Sorry, Emerson, I can't help ya on your dial indicator issue. Obviously I have never done timing myself, hence my clarifiaction questions. :-laf

 

[JGheen]

JGheen read back a couple posts. . . the exhaust valve is open for the whole engine rotation because it is way overtightened to force it open. Note: don't rotate engine past the point where it normally would open the valve because then you can cause valve spring bind/damage. In this case rotate engine 1 revolution then tighten the valve and do the procedure.



I never heard of this procedure before but it should work very well. BTW I have my head off right now doing the headgasket. . . do you think now would be a good time to mark TDC??



Vaughn

Yeah, I figured it out after I thought more into it. Sometimes written explainations are not easy for me to understand.



Yes, I am sure TDC would be easily found when the piston is exposed from the head removal.

 

[Howard Durand]

Make sure you are reading the dial properly.